In the present specification, the term "loose leafs" is used to mean any plurality of flexible sheets that may be used or stored together in a generally flattened arrangement, such as sheets of paper. It will, of course be understood, that where the term "papers" is used, this is also intended to include other paper-like sheets.
There have long been known in the art devices, such as paper clips, for clipping together a number of papers. A particular problem arises with regard to clipping together a number of loose-leaf pages which have been inserted into a loose-leaf binder or file folder. In this case, papers are generally punched and thereafter filed in a desired order. If it is necessary to remove one or more selected pages from within a stack of pages filed in the loose-leaf binder or file folder and then restore to the file the pages originally located above the selected pages,, the pages which were filed after the selected pages must be removed before the selected pages can be removed, and then replaced in the folder in the same order after the selected pages have been either permanently removed or refiled.
The most common filing method involves punching two holes in one edge of the pages to be filed. The punched pages are then inserted through a fastener, generally comprising two bendable prongs, the base of which is secured to the folder by passing the prongs outwardly through two holes punched in a flap which is an integral part of the folder. The filed pages may be secured by either bending the protruding portions of the prongs against the top page, or against a retaining device which comprises two holes for inserting the prongs and two sliding retainers for retaining the bent prongs.
Removal of pages from this fastener requires sliding the retainers (in case a retaining device is being used), straightening the bent portions of the prongs and sliding the pages therealong. Replacement of the removed pages requires sliding them through the punched holes back onto the prongs. Thus, removal and reinsertion of punched pages in a file folder of this kind is often time consuming and tedious, especially when said selected pages are located near the bottom of the stack of pages filed in the folder and the pages must be removed and reinserted one by one.
A number of solutions to this problem have been proposed. These include devices such as those disclosed in U.S. Pat. Nos. 5,169,255, 895,268 and 4,790,680 which are designed to grip the pages above the selected pages and to hold them as a single unit while they are removed, to permit removal of the selected pages, and replaced thereafter. These devices are all spring biased in the closed or gripping orientation, requiring application of a force by a user so as to open them in order to permit the insertion therein of papers.
These devices all suffer from the disadvantage that the strength of gripping is limited to the spring which biases the device which, in turn, limits the number of pages which can be tightly gripped by the device. Thus, if the number of pages to be gripped is relatively large, these devices are unable to grip them firmly, and the pages tend to move relative to one another during removal and replacement.